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What Do Horses Eat? An Equine Nutrition Guide

Last updated: June 21, 2023

By: Miles HenryFact Checked

A horse’s digestive system is complex and fragile, and to keep it running smoothly, a horse needs to eat the right food. If they don’t eat correctly, they’re likely to get sick, display changes in behavior, and can colic. So, what do horses need to eat?

Horses eat grass and other vegetation; they also consume hay, oats, and other grains, as well as occasional treats like carrots or apples. Horses have small stomachs that process food quickly. So, to meet their dietary needs, they are constantly grazing.

When horses don’t get enough of what they need, it negatively impacts their health and behavior. This article is part of a series of articles I wrote about equine nutrition; I encourage you to use the links for detailed information on specific topics.

Understanding Equine Digestion

The process of digestion in horses is a fascinating topic and one that’s essential to understanding how to properly feed and care for these animals.

Picture of a thoroughbred stallion.

Anatomy of a Horse’s Digestive System

The horse’s digestive system is a complex and efficient structure designed to extract the maximum nutrition from a diet primarily based on plant material. It comprises several parts, each with a unique role:

  1. Mouth: The process starts here, where food is taken in and chewed, mixed with saliva, and formed into a ball called a bolus.
  2. Esophagus: The food travels down this muscular tube to reach the stomach.
  3. Stomach: The horse’s stomach is small compared to its body size, holding only about 2-4 gallons. Here, food is mixed with stomach acids to begin the breakdown process.
  4. Small Intestine: The broken-down food then moves into the small intestine, which is the main site for digestion and absorption of proteins and carbohydrates, along with some minerals and vitamins.
  5. Cecum: In this large “blind pouch” – the beginning of the large intestine – bacterial fermentation breaks down fibrous materials like hay and grass.
  6. Large Colon: Further fermentation occurs here, and the majority of water and electrolytes are absorbed.
  7. Small Colon: The remaining material is formed into fecal balls in the small colon, and water absorption continues.
  8. Rectum: Finally, waste products are expelled through the rectum.
Picture of a horse eating from a hay bag.

Process of Digestion in Horses

The horse’s digestion process is designed to efficiently break down fibrous plant materials and extract necessary nutrients. When a horse eats, it chews the food, mixing it with saliva to start the digestive process. The food then travels down the esophagus into the stomach, where it’s further broken down by stomach acids.

This mixture then moves into the small intestine. Here, enzymes break down the proteins and carbohydrates into simpler molecules, which are absorbed into the bloodstream. The food that remains, primarily the fibrous content, passes into the cecum and the large colon, where it undergoes bacterial fermentation.

This process breaks down the fiber into volatile fatty acids, which provide a significant portion of a horse’s energy needs. Finally, after the nutrients are extracted, the leftover waste material, primarily undigested fiber, water, and electrolytes, passes through the small colon, where it’s formed into fecal balls, before being expelled from the body through the rectum.

Understanding the structure and function of the equine digestive system is crucial to feeding horses correctly and maintaining their digestive health. Each step in this process plays an integral part in how a horse breaks down food, absorbs nutrients, and manages waste.

Picture of horses in a pasture

Natural Diet of Horses

The natural diet of horses is rather simple yet nutritionally balanced. It consists largely of grasses and plant materials, a dietary preference that has been shaped by millions of years of evolution.

Horses are designed to graze and have developed as ‘hindgut fermenters,’ which means they’re equipped to extract nutrition from plant fibers that many other animals can’t digest. They are built to eat frequently, slowly ingesting and processing plant materials throughout the day.

When you consider a horse grazing in a pasture, the bulk of what they’re eating is grass. The types of grasses they consume can vary depending on the region and the season, but common varieties include Timothy, Bermuda, fescue, and bluegrass. In addition to grasses, horses also eat various plants, herbs, and even tree bark or branches.

This natural diet provides horses with a rich source of fiber. Fiber is critical for their digestive health and forms the majority of their energy source. Grasses also contain essential nutrients, such as proteins, fats, and a variety of vitamins and minerals. These elements are vital for maintaining overall health, muscle development, and various bodily functions.

Wild horses would naturally consume a diverse array of grasses and plants, which allows them to get a balanced mix of these nutrients. However, domesticated horses’ diets are often supplemented with hay and prepared feeds to ensure they receive all the necessary nutrients.

The concept of a horse’s natural diet is a central tenet of equine nutrition. By understanding what horses are designed to eat, we can make better decisions about how to feed domesticated horses and provide the best care for their unique nutritional needs.

Picture of square bales of hay.

Common Feed for Domestic Horses

Feeding domestic horses involves a careful balance of various food sources to meet their nutritional needs. Let’s explore some of the most common types of feed.

Hay

Hay is a staple in the diet of most domestic horses. It’s dried grass or legumes, which helps preserve it and allows for feeding during times when fresh pasture isn’t available. There are different types of hay, and their nutritional content varies:

  1. Grass Hay: This includes types like Timothy, orchard grass, and Bermuda grass. They’re generally lower in protein and energy but high in fiber, making them good for mature, idle horses.
  2. Legume Hay: This includes alfalfa and clover. These hays are higher in protein, energy, and calcium, making them ideal for young, growing horses, lactating mares, or high-performance horses.
  3. Mixed Hay: A combination of grass and legume hays, offering a balanced nutrient profile.

Important Reminder: Proper storage of hay bales is crucial to maintain freshness and prevent mold growth, thereby ensuring your horse receives high-quality, safe hay.

Fresh Pasture

Fresh pasture is a significant and natural source of nutrition for many domestic horses, and it’s particularly valuable during the grass-growing season. Grazing on pasture not only provides nutritional benefits but also satisfies a horse’s natural instinct to graze, offering mental health benefits as well.

  1. Grass: The types of grasses available in a pasture can vary greatly based on geography, but common types include Kentucky bluegrass, Bermuda grass, Timothy grass, and ryegrass. Fresh grass is an excellent source of energy, protein, and other nutrients. It’s also high in water content and provides a significant amount of fiber. However, don’t let your horse eat lawn clippings.
  2. Nutritional Value: Fresh grass typically has a higher nutritional value compared to hay because it’s consumed at its peak nutritional state without undergoing the drying process that hay goes through.
  3. Rotation and Maintenance: It’s essential to manage pastures carefully to prevent overgrazing, which can deplete the nutritional value and even damage the pasture. Rotational grazing, where different sections of the pasture are sectioned off and grazed in turns, can help maintain a healthy and nutritious pasture.

Including fresh grass in a horse’s diet can contribute significantly to their overall health and well-being. However, as with other feeds, it’s important to monitor the horse’s condition and adjust the amount of grazing time based on individual nutritional needs.

Grain

Grains provide concentrated energy and can be a valuable part of a horse’s diet, especially for those with high energy demands.

  1. Corn: High in energy but low in protein and fiber. It should be cracked or rolled for better digestion, and care should be taken not to overfeed as it can lead to obesity.
  2. Oats: One of the safest grains to feed due to their high fiber content. They are more easily digested than other grains.
  3. Barley: It must be processed (usually rolled or crushed) for horses to digest effectively.

Grains should be introduced gradually into a horse’s diet and should always be fed alongside hay or pasture to ensure sufficient fiber intake.

Pellets and Mixes

Pellets and mixes are manufactured feeds that are designed to provide a balanced diet.

  1. Pelleted Feed: These are made by grinding up grains such as wheat and other feed components and pressing them into small pellets. They are easy to digest and reduce the risk of selective eating.
  2. Textured or Sweet Feed: This is a mix of grains, molasses, and often added vitamins and minerals. They are palatable but can be high in sugar.
  3. Complete Feed: These include all necessary nutrients and are designed to be fed as the horse’s sole ration, without the need for additional hay or pasture.

Pellets and mixes are often beneficial for horses with specific nutritional needs, for those with dental issues that prevent them from eating hay, or when high-quality hay is not available.

Remember, all changes to a horse’s diet should be made gradually, and it’s important to consider their individual needs, including their age, size, activity level, and overall health. Consulting with a veterinarian or equine nutritionist can be helpful in creating an optimal feeding plan.

Picture of a horse licking a salt block.

Understanding Horse Nutrient Requirements

Horses, like all living organisms, need a balanced diet that meets their specific nutritional requirements. Understanding these requirements and how they are met is crucial for maintaining a horse’s health and well-being.

Proteins

Proteins are essential for a variety of functions in a horse’s body, including muscle development and repair and the production of enzymes and hormones. The primary sources of protein in a horse’s diet are hay, grass, and legumes. For example, alfalfa hay and clover are particularly high in protein. Commercial feeds and supplements can also provide necessary protein.

Vitamins and Minerals

Vitamins and minerals are required in small but essential amounts for various functions, from bone health to nerve function. The horse’s diet usually supplies most of these. For instance, fresh pasture, hay, and grains can provide a variety of vitamins and minerals. However, in some cases, a mineral block or supplement may be needed to ensure the horse is getting everything it requires.

Water

Water is a vital nutrient that is often overlooked. It aids digestion, regulates body temperature, and is involved in almost every bodily function. Horses should always have access to clean, fresh water. They generally drink between 5 and 10 gallons a day, but this can increase substantially in hot weather or with exercise.

Carbohydrates

Carbohydrates are the primary source of energy in a horse’s diet. They can be found in all feeds, including grasses, hays, and grains. However, not all carbohydrates are created equal. Structural carbohydrates, like fibers in hay and grass, are slowly digested and provide long-lasting energy.

Non-structural carbohydrates, like sugars and starches found in grains, provide quick energy but can cause health problems like laminitis and colic if consumed in excess.

Understanding the nutritional needs of horses is the first step in ensuring their diet is balanced and healthy. Always consider the horse’s age, size, workload, and overall health status when determining its diet, and consult with an equine nutritionist or veterinarian to ensure all nutritional needs are being met.

Minimum Nutritional Requirements Chart for Horses.

Type of HorseCrude Protein
(% of daily ration
Energy
(calories)
Vitamin “A”Calcium
(international units)
Phosphorus
Mature at rest
900lbs.
1100lbs.

10 %
13,860-16,39010,000-12,50016,000-20,00012,000-15,000
Mature at light work10%18,360-21,89010,000-12,50016,000-20,00012,000-15,000
Mature at moderate work10%23,800-28,69010,000-12,50017,200-21,20013,000-16,000
Mare in last 90 days of pregnancy11.5%14,880-17,35020,000-25,00019,500-24,00015,000-18,000
Lactating Mares13.3%-24,390-27,62020,000-25,00042,000-47,00035,600-38,600
Foals (3 mos.)19%12,0704,40030,50019,100
weanlings (6 mos.)14.3%15,4009,00046,00028,700
Yearlings12.3%16,81011,00026,00017,400
18 month11.3%17,16016,00023,00016,000

The chart numbers represent a daily feeding ratio for a healthy mature horse at light work (1 to 3 hours daily) that weighs approximately 1,000 pounds. This feeding would meet the recommended daily rations to maintain a healthy horse.

Equestrians generally use a standard-sized scoop for feed; remember that all grains don’t weigh the same. For this reason, check the weight of the grain, and feed the correct amount. Remember to introduce a new feeding plan slowly and consult your veterinarian if you have any questions concerning your horses’ health.

Special Dietary Considerations for Horses

As human dietary needs change with different stages of life, activity levels, and health conditions, the same goes for horses. A horse’s diet must be carefully managed and adjusted according to their age, activity level, and health status. Let’s break this down further:

A. Diet Changes Based on Age and Life Stage

Foals, adult horses, and seniors each have unique nutritional needs.

  1. Foals: Young horses have a high demand for nutrients to support their rapid growth. A diet rich in quality protein, calcium, and phosphorus is critical for muscle and skeletal development. Initially, they rely on their mother’s milk, but by 2-3 months, they start nibbling on grass and grain, and by 6 months, solid food becomes a significant part of their diet.
  2. Adult horses: Adult horses’ dietary needs depend largely on their activity level, which we’ll explore next. Generally, their diet should be balanced and rich in fiber, with adequate protein, vitamins, and minerals.
  3. Senior horses: As horses age, they may face dental issues making it hard to chew long-stem hay, their metabolism may slow down, and they may become less efficient in absorbing nutrients. A diet with easily digestible fiber, higher protein, and fortified with vitamins and minerals can help meet their nutritional needs.

B. Dietary Needs for Different Levels of Activity

A horse’s energy requirements increase with its level of activity.

  1. Sedentary horses: For horses that get little to no exercise, a diet based primarily on forage, like grass or hay, can fulfill their nutritional needs.
  2. Working horses: Horses that work hard, whether in sports, farming, or other activities, require a diet with more energy-dense feeds, such as grains or commercially prepared high-energy feeds.
  3. Pregnant or lactating mares: These horses have increased nutritional needs to support the growth of the foal and milk production.

C. Addressing Health Issues Through Diet

Certain health issues in horses can be managed or even prevented through proper diet.

  1. Laminitis: This painful condition can be triggered by overconsumption of carbohydrates. Limiting access to lush pasture and avoiding high-carb feeds can help manage the risk.
  2. Metabolic disorders: Conditions such as Equine Metabolic Syndrome and Cushing’s disease can be managed with a diet low in non-structural carbohydrates, along with controlled grazing.
  3. Obesity: Like humans, horses can become overweight, leading to various health problems. A carefully controlled diet and regular exercise are key to weight management.

Providing the right nutrition based on a horse’s individual needs is crucial for their health and well-being. Always consult with a veterinarian or an equine nutritionist to tailor the dietary plans for your horse.

horse on the Irish plain

Common Feeding Mistakes to Avoid

Feeding horses might seem straightforward, but there are many nuances to consider to ensure their nutritional needs are met. Here are some common mistakes to avoid, as well as solutions for better practices:

Common Errors in Horse Nutrition

  1. Inconsistent Feeding Times: Horses are creatures of habit. Feeding them at inconsistent times can stress their digestive system.
  2. Rapid Changes in Diet: Abruptly changing a horse’s diet can lead to digestive upsets or even severe disorders like colic.
  3. Overfeeding Grain: Too much grain can lead to obesity, and if eaten quickly, can cause serious issues like colic and laminitis.
  4. Insufficient Water: Lack of adequate fresh water can lead to dehydration and impact digestion.
  5. Not Adjusting Diet for Workload: Failing to increase food intake for working horses can lead to weight loss and poor performance.
  6. Neglecting Dental Care: If a horse’s teeth aren’t properly maintained, it can have difficulty chewing and digesting its food.

Solutions and Better Practices

  1. Consistent Feeding Schedule: To align with their natural grazing habits, try to feed your horse at the same times each day.
  2. Gradual Diet Changes: If you need to change your horse’s diet, do so gradually over a period of several weeks.
  3. Balanced Grain Intake: Feed grain in small amounts and only as necessary depending on the horse’s energy requirements. Remember, the bulk of a horse’s diet should be forage.
  4. Provide Fresh Water: Always ensure your horse has access to fresh and clean water.
  5. Adjust Diet for Workload: If your horse is more active, adjust its diet accordingly, providing more energy-dense feed.
  6. Regular Dental Check-ups: Schedule regular dental check-ups for your horse to ensure it can chew its food properly.
  7. Consultation with Professionals: Working with an equine nutritionist or a veterinarian can help tailor your horse’s diet to its specific needs and avoid potential pitfalls.

By avoiding these common mistakes and following better practices, you can provide a balanced diet that supports your horse’s health and well-being.

Some Common Foods You Should Not Feed a Horse.

There are many things we eat that shouldn’t be fed to horses; it would be impossible to cover all foods that are harmful to horses, but here are the more common food items most people have around their house that shouldn’t be fed to horses:

  • Coffee, tea, or any drink that contains sugar or caffeine.
  • Candy, especially chocolate. The chemical theobromine in chocolate can make a horse sick and, in some instances, be fatal. Sugar cubes should be limited as well.
  • Tomatoes: It’s mainly the tomato plant that causes the most severe trouble. Their leaves and stalks contain an alkaloid that slows gut function and can cause colic.
  • Onions, garlic, leeks, and shallots can cause a horse to become anemic if ingested. If a horse eats enough of one of these, the condition could be life-threatening.
  • Potatoes have a natural toxin called glycoalkaloids. Therefore, when horses eat large amounts of potatoes, they will get sick and may never fully recover.
  • Feeding your horse vegetables from the cabbage family, including turnips, cabbages, kale, and broccoli, can result in noticeable discomfort and excessive gas.

While it’s tempting to spoil our horses with treats, it’s crucial to remember that not all treats are safe or healthy for them. Some can even pose significant health risks.

Picture of horses eating watermelons

Horses Eat Fruits and Vegetables.

Most horses aren’t picky eaters when it comes to fruits and vegetables. They eat apples, carrots, watermelons, and many other fruits and vegetables. However, there’s one crucial thing you need to know before feeding your horse fruit and vegetables, and it’s that each has different risks associated with it, and some can make an animal sick.

But many fruits and vegetables provide benefits, such as being rich sources of nutrients. So please don’t feed your horse anything you aren’t sure is safe for them to eat. For example, we cut up watermelon rinds before feeding them to our horses.

Below is a helpful YouTube video about what horses eat and drink.

YouTube video

Conclusion

Feeding a horse involves much more than simply providing food. Understanding the complexities of equine nutrition, from the specifics of their digestive system to the particular requirements for proteins, vitamins, minerals, water, and carbohydrates, is vital for their health and longevity.

It’s essential to keep in mind that each horse is an individual with unique nutritional needs depending on their age, workload, health status, and lifestyle. Knowing the value of different feeds such as hay, grains, fresh pasture, and manufactured pellets or mixes can help to ensure a balanced and suitable diet.

Avoiding common feeding mistakes—like inconsistent feeding times, abrupt dietary changes, and neglecting regular dental check-ups—is crucial to prevent health problems. Remember, good practices around feeding aren’t just about what to feed but also how and when.

FAQs

Do horses eat meat at all?

No, horses do not eat meat. They are herbivores, meaning their diet consists primarily of plant-based foods like grasses, hay, and certain fruits and vegetables. Their digestive system is not equipped to process meat.

What food do wild horses eat?

Wild horses primarily graze on a variety of grasses and other vegetation available in their habitat. They may also consume bark, leaves, and certain fruits or berries when available. Their diet is largely dependent on the season and the specific vegetation of their geographical location.

Why do horses eat dirt?

Horses may occasionally eat dirt due to nutritional deficiencies, particularly if they lack minerals in their diet. They might also ingest dirt accidentally while grazing or if they’re bored. However, excessive dirt eating can lead to health issues, like colic, so it’s important to consult a vet if this behavior is noticed.

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